Disk drives used in small electronic devices such as laptops, MP3 players, GPS, PDA devices and other devices are “mobile drives.” Slider air bearing is a key component of these “mobile drives.” Some of the requirements of these “mobile drives” include “low altitude sensitivity” and “high operational shock” performances.
The low altitude sensitivity means that the slider air bearing has a small fly height (FH) loss at a higher altitude (such as 3000 meters) compared to the FH at sea level. The requirement for a small FH loss becomes more important for current drives with sub 10 nanometer FH. The high operational shock requirement means that the slider air bearing would not collapse and the slider/disk interface damage would not occur during operating state when the drive experiences a very high acceleration such as impact, free drop, etc. The highest acceleration value without the interface damage is called the “op-shock” boundary. Current specification for the op-shock boundary is approximately 200 G and 2 ms duration, however, the specification is getting higher, such as 400 G/2 ms.
To reduce FH loss, a low base recess (low depth etch) or a dimple forward slider is used. However, a low base recess reduces op-shock performance and the dimple forward design degrades the op-shock also. A deeper base recess increases op-shock performance, however, the FH loss suffers drastically. The requirements of high op-shock and low FH loss are at conflict. Conventionally, FH loss has been minimized at the expense of high op-shock degradation.